Plantation Management on Cd Contaminated Area: Case Study Mae Sot, Tak Province, Thailand

Transcription

1 Plantation Management on Cd Contaminated Area: Case Study Mae Sot, Tak Province, Thailand Chantra Tongcumpou Environmental Research Institute, Chulalongkorn University National Excellence Center for Environmental and Hazardous Waste Management, Chulalongkorn University 18 February

2 Introduction and Background 2

3 Cd contaminated in soil and rice in Mae Toa Source IWMI ( )

4 Why needs plantation management? Extensive area found to be contaminated with Cadmium. This area has been used for agriculture for several decades Most of people living in these areas sustain as farmers. To suspend the area for cultivation and compensate by the government cannot be sustained. To abandon the area for remediation may not be appropriated for this case either. 4

5 Researches Conducted by NCE-CU Project I: Cadmium Distribution and Bioavailability in Cultivated Soil and Crops in the Vicinity of Zinc Mine in Mae Sot ( ) Project II: Zoning of Cadmium Level in Flood Plains Area of Mae Tao and Mae Ku Subcatchments (2006) Project III: Sugarcane Cultivation in Former Cadmium Contaminated in Paddy Soil ( ) 5

6 Project I: Cadmium Distribution and Bioavailability in Cultivated Soil and Crops in the Vicinity of Zinc Mine in Mae Sot Objectives What level of Cadmium distributed in this area? Where Cadmium come form and how? Relation of Cd in soil and in plant (rice)? 6

7 Study Area and Soil Sampling

8 Cd Concentrations in Stream sediment

9 Surface Water Sampling m. N m. N m. E m. E P13 P11 P10 ( P12 ( P11 ( P kilometres Sampling Station P10 Sampling Station P11 Phadaeng mining Tak Mining Sampling Station P12 and P13 9

10 CD and Zn concentrations in Surface Water Sample Labels 1. Pond 2. Pond closed to a factory 3. Pond in paddy field 4. Pond near paddy filed 5. Pond near mice field 6. Pond near the textile factory 7. Pit along road 8. Pit for cattle 9. Pond near paddy field 10. Settling pond Settling pond Settling pond 3 (before filtering) 13. Settling pond 3 (after filtering) Concentration in solution form (mg/l) Cd < < < < < < Zn < < < < < < < < <

11 Soil Solution Sampling in Selected Sites 11

12 Cd concentrations in Soil, Soil Solution and Rice Grain 10 Cadmium conc. (ppm) Soil Soil solution Rice grain Plot no. of paddy field 12

13 Outcomes from the Project I Cd in flood plain of Mae Toa had been distributed from the erosion upland in form of sediments. Cd concentration in soil solution (available form) directly correlated to Cd in rice grain but not linearly correlated with total Cd in soil. Cd found mainly uptake to rice during the drainage period before harvesting ph and redox potential are two key factors influence Cd uptake. 13

14 Project II: Zoning of Cadmium Level in Flood Plains Area of Mae Tao and Mae Ku Subcatchments Objective To classify and zoning the level of Cd concentrations in Mae Toa and Mae Ku sub-catchments covered the area of three sub-district; Mae Toa, Mae Ku and Pha Taad Padeang. 14

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16 Zoning Area of Cd Concentration levels in Mae Toa, Mae Ku and Pra Taad Padeang Zone of contamination Cd conc. range (mg./kg.) Area (hectare) Area (rai) % Un-contamination < 3 7,485 46, Low contamination ,504 21, Medium contamination High contamination > , Total area - 11,325 70, Average Cd content in soil in Thailand is 0.03 gm/kg Source: Zarcinas et al (2004) 16

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18 Concept of Plantation Management Introduce plants that are not edible or not be in the food chain. Farmers should sustain and can still use their land for agriculture. Agricultural practice and marketing of the product should be supported from related agencies. Monitoring for Cd uptake should be followed up for the new plants. Evaluation of the impact of the new plants should be investigated. 18

19 Project III: Sugarcane Cultivation in Former Cadmium Contaminated in Paddy Soil Objectives To determine the Cd uptake from soil to sugarcane from different area of contaminations. To investigate the correlation of Cd uptake to different part of sugarcane. 19

20 Sample Collecting from Plantation Sites 177 samples of both soil and sugarcane were collected from Zone 1: < 3.0 mg Cd /kg soil Zone 2: mg Cd /kg soil Zone 1: >20.0 mg Cd /kg soil Additional 54 samples of soil and sugarcane were collected in October

21 Sugarcane Plantation Cd Contaminated Area Pra Taad Padeang Symbol District boundary MaeToa Study Area Mae Ku Sugarcane Planting Zinc mines Cadmium concentration levels < 0.30 mg/kg 3-20 mg/kg >20 mg/kg 21

22 Sampling sites for soil and sugarcane Symbol Pra Taad Padeang District boundary Study Area MaeToa Sugarcane Planting Zinc mines Mae Ku Cadmium concentration levels < 0.30 mg/kg 3-20 mg/kg >20 mg/kg 171 Sampling sites 54 additional sites 22

23 Soil and Sugarcane Sampling 23

24 Sugarcane Samples Preparation 24

25 Sugarcane Part Divided for Cd Analysis Top Leave Juice and bagasse Underground stem Root 25

26 Squeezing to separate juice and bagasse 26

27 Cd concentrations in Soil and Sugarcane Soil Root Underground stem Bagasse Juice Leave Top Min Max Mean Median Cd (mg/kg)

28 Cd Distributions in Soil Samples 120 Cd in soil (mg/kg) Total Samples of Soil Cd Conc. No. % > Cd (mg/kg) > 2.0 > 3.0 > 5.0 > > Min No. of samples Mean Max Only 8% of soil samples exceed Cd conc. for soil standard 28

29 Cd Distributions in Root Samples Cd (mg/kg) Cd in root (mg/kg) No. of samples Total Samples of Root Cd Conc. No. % > > > > > > Min Mean Max Less than 15% of root samples have Cd content higher than 5.0 mg kg 29

30 Cd Distributions in Bagasse Samples 5.0 Cd in Bagasse (mg/kg) Total Samples of Bagasse Cd conc No. % Cd (mg/kg) >0.25 > 0.5 > > No. of samples > Min Mean Max Only 1.9% of bagasse samples have Cd content higher than 3.0 mg/kg. 30

31 Cd Distributions in Juice Samples 0.6 Cd in juice (mg/l) Total Samples ofjuice Cd (mg/l) No. of samples Cd conc > 0.05 > 0.10 > 0.2 > 0.3 > 0.5 No Min Mean Max % Only 1.2% of juice samples have Cd content higher than 0.3 mg./l 31

32 Cd Distributions in Juice Samples 4 Cd in Top (mg/kg) Total samples oftop Cd conc No. % Cd (mg/kg) > 0.1 > 0.25 > 0.5 > 1.0 > Min Mean No. of samples Max Only 5.6% of top samples have Cd content higher than 1.0 mg./l 32

33 Relationship of Cd in Soil and Sugarcane 100 Zone 1 Zone 2 Zone months Cd in sugarcane (mg/kg) Root Bagasse Juice Top Cd in soil (mg/kg) 33

34 Cd Accumulated in Juice at Age 8-10 Months Cd Accumulated in Juice (mg/l) Total Zone 1 Zone 2 Zone 3 Min Max Mean S.D Median Mode

35 Conclusions for the First Year Study Cd uptake from soil to sugarcane are accumulated mainly in root. Cd accumulated in bagasse, top and juice are limited at certain level, especially for juice found that the Cd accumulated less than 0.5mg./L Correlation between Cd in soil and and sugarcane are not linearly regression especially at high level of Cd in soil. 35

36 Other Concerns from People in the Area Some people still want to grow rice. To compromise the problem in Mae Sot, other studies should be done: Investigate how to grow rice without uptake Cd? Investigate how to immobilize Cd or reduce Cd bioavailable form? Investigate if rice can be grown for seedling purpose? These ideas lead to other related research 36

37 Other Studies ongoing in the Area An evaluation of Soil and irrigation management options to limit the uptake of Cd to rice plant in Cd contaminated soils (accomplished). Effect of other metals on Cd uptake by sugarcane (ongoing). Bioavailable Cd and Zn in soil in sugarcane cultivation area : Mae Sot (ongoing). Utilization of Cd-contaminated seed as rice seeding (ongoing). 37

38 There is no single solution can solve a problem. 38

39 Thank you for your attention 39